The present invention relates generally to keyboards, including typewriter and computer keyboards.
More specifically, the present invention relates to keyboards having illuminated key members.
Conventional keyboards include a plurality of key members which display symbols, such as alphanumeric keys, on their top surfaces. Moreover, typical modern keyboards, such as those found in cellular telephones, Automatic Teller Machines (ATMs), electric typewriters and computers utilize a make-and-break electrical circuit which is activated by depression of a key member for identifying a particular symbol embedded on the top of the key member.
A problem with prior art keyboards is that it is often difficult to discern the symbol appearing on the top of the key member under poor lighting conditions. This causes the keyboard operator to memorize the key locations or to strain their eyes to operate the keys of the keyboard under low light conditions. This has become a much greater problem in present day society as keyboards have become necessary for everyday use and as keyboard use is not limited primarily to operation by workers in business offices as in the past. As a result of this expansion of keyboard use, more and more operators have less training on keyboards, and correspondingly many keyboard operators utilize a “hunt and peck” style of keyboard operation.
Moreover, the advent of laptop and notebook computers has resulted in the use of keyboards at places where they were not previously operated. Often these places provide limited light making it difficult for keyboard operators to quickly and easily operate the keyboard. For example, it is a common sight on commercial aircraft to see a passenger slowly hunt and peck at their keyboards continuously looking at the key members to verify that they are in fact pressing the correct keys.
Accordingly, it is clear that there is a need for an apparatus that makes keyboard key members more discernable in low light conditions. Backlighting is commonly used in rubber keypads, membrane switches, rigid panels and the like to make them more visible and discernable. These keypad panels typically make use of light emitting crystals (LECs), light emitting diodes (LEDs), and/or fiber optics for this purpose. Most prior backlit keyboards utilize a light source which is typically transmitted via a fiber optic cable to the key members of a keypad. For example, U.S. Pat. No. 5,034,602 issued to Garcia, Jr. et al. discloses an optically activated keyboard which uses fiber optic cables to transmit light to translucent key members. The light is transmitted through the translucent key members where it is emitted from the top of the key cap. Similarly, U.S. Pat. No. 3,886,544 issued to Narodny and U.S. Pat. No. 5,097,396 issued to Myers disclose keyboards which use backlighting. Each key member in connection to a fiber optic cable which transmits light to a respective key member which thereafter transmits light from the top of the key cap. Additional keyboard and keypad techniques include the LED and LEC backlighting commonly utilized for alarm activator and deactivator keypads wherein each key includes a separate LED or LEC structure embedded in or behind the key member. Unfortunately, it is extremely difficult to route fiber optics to the keyboard keys of today's computer systems. For example, it would be particularly difficult to route fiber optic cables and provide a light source to the key members of today's notebook computers and palm-sized computer systems.
In addition, the light sources for use with prior art backlit keyboards require substantial power and in some cases, a fan for cooling which draws additional power. These constructions are prohibitive for portable computers such as laptop and notebook computers which draw on the power of a rechargeable battery and where power is at a premium.
Recently, the present named inventor, Michael Shipman, developed numerous lighted keyboard and light pipe constructions which are the subject of U.S. Pat. No. 6,217,183 issued on Apr. 17, 2001; U.S. Pat. No. 6,467,924 issued on Oct. 22, 2002; U.S. Pat. No. 6,918,677 issued on Jul. 19, 2005; U.S. Pat. No. 7,172,303 issued on Feb. 6, 2007; U.S. Pat. No. 7,193,535 issued on Mar. 20, 2007; U.S. Pat. No. 7,193,536 issued on Mar. 20, 2007; and U.S. Pat. No. 7,283,066 and which are incorporated by reference herein. The keyboard constructions utilize a variety of electro luminescent, light transmitting panels and light emitting diodes (LED) for illuminating the keys of a keyboard. For the most part, these constructions are satisfactory.
It would be highly advantageous to provide a keyboard having illuminated key members which provided improvement in weight and simplicity; was inexpensive to manufacture; and required low power consumption.